Abstract: A DRAM capacitor may include a first capacitor electrode, a capacitor dielectric adjacent to the first capacitor electrode, and a second capacitor electrode adjacent to the capacitor dielectric. The first capacitor electrode may include a lower portion, an upper portion, and a step transition between the lower portion and the upper portion, a width of the upper portion of the first capacitor electrode at the step transition is less than a width of the lower portion of the first capacitor electrode at the step transition. Semiconductor devices, systems, and methods are also disclosed.

Abstract: A method for forming a memory device includes the steps of providing a substrate, forming an isolation structure in the substrate to define a plurality of active regions in the substrate, the active regions respectively comprising two terminal portions and a central portion between the terminal portions, forming a plurality of island features on the substrate, wherein each of the island features covers two of the terminals portions respectively belonging to two of the active regions, performing a first etching process, using the island features as an etching mask to etch the substrate to define a plurality of island structures and a first recessed region surrounding the island structures on the substrate, and removing the island features to expose the island structures.

Abstract: A method for fabricating semiconductor device includes the steps of: forming a semiconductor layer on a substrate; removing part of the semiconductor layer and part of the substrate to form a trench; forming a liner in the trench; removing part of the liner to form a spacer adjacent to two sides of the trench; forming a conductive layer in the trench; forming a metal layer on the conductive layer; forming a mask layer on the metal layer; and patterning the mask layer, the metal layer, and the conductive layer to form a bit line structure.

Abstract: A DRAM capacitor may include a first capacitor electrode, a capacitor dielectric adjacent to the first capacitor electrode, and a second capacitor electrode adjacent to the capacitor dielectric. The first capacitor electrode may include a lower portion, an upper portion, and a step transition between the lower portion and the upper portion, a width of the upper portion of the first capacitor electrode at the step transition is less than a width of the lower portion of the first capacitor electrode at the step transition. Semiconductor devices, systems, and methods are also disclosed.

Abstract: A method for forming a memory device includes the steps of providing a substrate, forming an isolation structure in the substrate to define a plurality of active regions in the substrate, the active regions respectively comprising two terminal portions and a central portion between the terminal portions, forming a plurality of island features on the substrate, wherein each of the island features covers two of the terminals portions respectively belonging to two of the active regions, performing a first etching process, using the island features as an etching mask to etch the substrate to define a plurality of island structures and a first recessed region surrounding the island structures on the substrate, and removing the island features to expose the island structures.

Abstract: A method for fabricating semiconductor device includes the steps of: forming a semiconductor layer on a substrate; removing part of the semiconductor layer and part of the substrate to form a trench; forming a liner in the trench; removing part of the liner to form a spacer adjacent to two sides of the trench; forming a conductive layer in the trench; forming a metal layer on the conductive layer; forming a mask layer on the metal layer; and patterning the mask layer, the metal layer, and the conductive layer to form a bit line structure.

Abstract: A method for forming a memory device is disclosed, including providing a substrate, forming an isolation structure and plural active regions in the substrate, forming a plurality of island features on the substrate respectively covering two of the terminal portions of the active regions, using the island features as an etching mask to etch the substrate to perform a first etching process to define a first recessed region and plural island structures on the substrate. The island structures respectively comprise the two terminal portions of the active regions and the first recessed region comprises the central portions of the active regions.

Abstract: According to an embodiment of the present invention, a method for fabricating semiconductor device includes the steps of: forming a semiconductor layer on a substrate; removing part of the semiconductor layer and part of the substrate to form a trench; forming a liner in the trench; removing part of the liner to form a spacer adjacent to two sides of the trench; and forming a bit line structure in the trench.

Abstract: According to an embodiment of the present invention, a method for fabricating semiconductor device includes the steps of: forming a semiconductor layer on a substrate; removing part of the semiconductor layer and part of the substrate to form a trench; forming a liner in the trench; removing part of the liner to form a spacer adjacent to two sides of the trench; and forming a bit line structure in the trench.

Abstract: A method for forming a memory device is disclosed, including providing a substrate, forming an isolation structure and plural active regions in the substrate, forming a plurality of island features on the substrate respectively covering two of the terminal portions of the active regions, using the island features as an etching mask to etch the substrate to perform a first etching process to define a first recessed region and plural island structures on the substrate. The island structures respectively comprise the two terminal portions of the active regions and the first recessed region comprises the central portions of the active regions.

Abstract: A method of fabricating a memory device includes forming a plurality of first insulative blocks and a plurality of second insulative blocks arranged in an alternating manner in a substrate, forming a plurality of wide trenches in the substrate to form a plurality of protruding blocks, forming a word line on each sidewall of the protruding blocks, isolating the word line on each sidewall of the protruding block, and forming an trench filler in the protruding block to form two mesa structures, wherein the first insulative block and the second insulative block have different depths, and the wide trenches are transverse to the first insulative blocks.

Abstract: A memory device includes a mesa structure and a word line. The mesa structure, having two opposite side surfaces, includes at least one pair of source/drain regions and at least one channel base region corresponding to the pair of source/drain regions formed therein. The word line includes two linear sections and at least one interconnecting portion. Each linear section extends on the respective side surface of the mesa structure, adjacent to the channel base region. The at least one interconnecting portion penetrates through the mesa structure, connecting the two linear sections.

Abstract: A memory device includes a plurality of isolations and trench fillers arranged in an alternating manner in a direction, a plurality of mesa structures between the isolations and trench fillers, and a plurality of word lines each overlying a side surface of the respective mesa. In one embodiment of the present invention, the width measured in the direction of the trench filler is smaller than that of the isolation, each mesa structure includes at least one paired source/drain regions and at least one channel base region corresponding to the paired source/drain regions, and each of the word lines is on a side surface of the mesa structure, adjacent the respective isolation, and is arranged adjacent the channel base region.

Abstract: A memory device includes a mesa structure and a word line. The mesa structure, having two opposite side surfaces, includes at least one pair of source/drain regions and at least one channel base region corresponding to the pair of source/drain regions formed therein. The word line includes two linear sections and at least one interconnecting portion. Each linear section extends on the respective side surface of the mesa structure, adjacent to the channel base region. The at least one interconnecting portion penetrates through the mesa structure, connecting the two linear sections.

Abstract: A method of forming a conductive contact includes forming a structure comprising an upper surface joining with a sidewall surface. The sidewall surface contains elemental-form silicon. Silicon is epitaxially grown from the sidewall surface. Dielectric material is formed over the upper surface and the epitaxially-grown silicon. A conductive contact is formed through the dielectric material to conductively connect with the upper surface.

Abstract: A memory device includes a plurality of isolations and trench fillers arranged in an alternating manner in a direction, a plurality of mesa structures between the isolations and trench fillers, and a plurality of word lines each overlying a side surface of the respective mesa. In one embodiment of the present invention, the width measured in the direction of the trench filler is smaller than that of the isolation, each mesa structure includes at least one paired source/drain regions and at least one channel base region corresponding to the paired source/drain regions, and each of the word lines is on a side surface of the mesa structure, adjacent the respective isolation, and is arranged adjacent the channel base region.

Abstract: A memory device includes a mesa structure and a word line. The mesa structure, having two opposite side surfaces, includes at least one pair of source/drain regions and at least one channel base region corresponding to the pair of source/drain regions formed therein. The word line includes two linear sections and at least one interconnecting portion. Each linear section extends on the respective side surface of the mesa structure, adjacent to the channel base region. The at least one interconnecting portion penetrates through the mesa structure, connecting the two linear sections.

Abstract: A method of forming a conductive contact includes forming a structure comprising an upper surface joining with a sidewall surface. The sidewall surface contains elemental-form silicon. Silicon is epitaxially grown from the sidewall surface. Dielectric material is formed over the upper surface and the epitaxially-grown silicon. A conductive contact is formed through the dielectric material to conductively connect with the upper surface.